1. Field of the Invention
The present invention relates generally to charged particle beam irradiation methods employed for fabricating microelectronic products. More particularly, the present invention relates to compensated charged particle beam irradiation methods employed for fabricating microelectronic products.
2. Description of the Related Art
Common in the microelectronic product fabrication art is the use of charged particle beam irradiation methods and apparatus for both metrologic purposes and processing purposes. Charged particle beams may include, but are not limited to, electron beams and ion beams. Within microelectronic product fabrication, electron beams are particularly common. They are employed within electron microscopy measurement methods, as well as electron beam photoexposure processing methods.
While charged particle beam irradiation methods are thus common in the microelectronic product fabrication art and often essential in the microelectronic product fabrication art, they are nonetheless not entirely without problems.
In that regard, charged particle beams are known to charge non-conducting substrates in a fashion which generally compromises a measurement accuracy or a processing accuracy of a charged particle beam irradiation method.
It is thus desirable in the microelectronic product fabrication art to provide charged particle beam irradiation methods and apparatus with enhanced accuracy.
It is towards the foregoing object that the present invention is directed.
Various charged particle beam methods having desirable properties have been disclosed within the microelectronic product fabrication art.
Included but not limiting among the methods are methods disclosed within: (1) Chen et al., in U.S. Pat. No. 5,783,366 (a photoresist implant method for eliminating charging effects within a scanning electron microscopy measurement method); and (2) Liu, in U.S. Pat. No. 5,962,867 (a test structure design which provides for attenuated charging during scanning electron microscopy measurement of integrated circuit products).
Desirable are additional charged particle beam irradiation methods with enhanced accuracy.
It is towards the foregoing object that the present invention is directed.
A first object of the invention is to provide a charged particle beam irradiation method for measuring or processing a microelectronic product.
A second object of the invention is to provide a charged particle beam irradiation method in accord with the first object of the invention, wherein the charged particle beam irradiation method has enhanced accuracy.
In accord with the objects of the invention, the invention provides a charged particle beam irradiation method for irradiating a substrate.
To practice the method of the invention,there is first provided a substrate having contained therein a areal region comprising an array of sub-regions intended to be irradiated with a corresponding series of shots of a charged particle beam. There is then irradiated the array of sub-regions with the series of shots of the charged particle beam, wherein a sequencing of irradiation of the array of sub-regions is geometrically determined such as to minimize a charged substrate induced charged particle beam deflection force when irradiating the series of sub-regions with the series of shots of the charged particle beam.
The present invention provides a charged particle beam method for measuring or processing a microelectronic product, wherein the charged particle beam method has enhanced accuracy.
The invention realizes the foregoing object within the context of irradiation of each of an array of sub-regions within an areal region of a substrate with a series of shots of a charged particle beam by sequencing the irradiation of each of the array of sub-regions geometrically such as to minimize charged particle beam deflection when irradiating the array of sub-regions with the series of shots of the charged particle beam.